Installation

WebTop Installation

Requirements

Operating system

WebTop should run on most Unix, Linux, macOS and Windows systems as long as Java and Apache Tomcat are available on this platform.

Java Virtual Machine

The required JRE version for a given WebTop release is:

WebTop release JRE version
5.2.0 and up Java 8
5.1.X Java 7
5.0.X Java 7

Warning

Java is missing support to UTF-7 so if you want to add it, you need to plug a third-party encoding implementation on the JRE:

  1. Download the JCharset jar from https://www.freeutils.net/source/jcharset/.
  2. Copy the file jcharset-2.0.jar to your $JAVA_HOME/jre/lib/ext directory. The JAR file has to be in exactly this directory for the class loader to pick it up.
  3. Restart Tomcat if it is running.

PostgreSQL Database

The required DBMS version for a given WebTop release is:

WebTop release PostgreSQL version
5.X.X and up 9.1 or greater with tablefunc, rrule_functions
5.11.0 and up 9.1 or greater with tablefunc
5.0.X and up 9.1 or greater

tablefunc

This package can be installed issuing the following SQL command:

CREATE EXTENSION tablefunc SCHEMA public;

Objects will be defined under the main public schema.

Note

If the above method do not work, you can always add object manually running tablefunc.sql SQL file against WebTop’s database from psql. You can find the file under PostgreSQL’s \contrib folder.

rrule_functions

This package is not part of the official PostgreSQL extensions, neither a contrib module. Functions are provided by the great DAViCal project.

These original procedures treat upper-bound dates in a inclusive manner: we have slightly modified them to make comparisons exclusive. So you can add these functions manually running rrule_functions.sql file against WebTop’s database.

Apache Tomcat

WebTop runs greatly on Tomcat 8.5 and 8.0, but we advice to use the most recent one.

Warning

WebTop may run on the older version 7 but is not reccomended due to early WebSocket support (with many reported bugs) and default use of BIO connectors.

Tomcat supports Parallel deployment that allows to deploy multiple versions of a Web application with the same context path at the same time. You can have more info here.

If you are planning to use this useful feature, each WebTop application instance must be made aware of the existence of the others in order to properly handle all the background tasks that compete for the data. Each instance will periodically monitor Tomcat in order to discover new instances and when found, it put itself in passive mode, gracefully shutting down every task. The newer instance will be the only one instance in active mode.

In order to implement this, you must enable access to Tomcat’s management by defining a dedicated user access in tomcat-users.xml file:

<user username="${MANAGER_USERNAME}" password="${MANAGER_PASSWORD}" roles="manager-script"/>

Note

Where ${MANAGER_USERNAME} is the choosen username and ${MANAGER_PASSWORD} is the choosen password.

The next and final step is to instruct the application about this access. This can be done in two ways:

  1. Use this SQL insert to apply configuration directly in Database:

    INSERT INTO "core"."settings" ("service_id", "key", "value") VALUES ('com.sonicle.webtop.core', 'tomcat.manager.uri', 'http://${MANAGER_USERNAME}:${MANAGER_PASSWORD}@localhost:${TOMCAT_PORT}/manager/text');
    
  2. Use these properties within webtop.properties configuration file (@since: wt.5.9.0):

    webtop.tomcat.manager.uri=http://${MANAGER_USERNAME}:${MANAGER_PASSWORD}@localhost:${TOMCAT_PORT}/manager/text
    

Note

Where ${TOMCAT_PORT} is the configured Tomcat’s port and ${MANAGER_USERNAME}, ${MANAGER_PASSWORD} are the values choosen above.

Run behind a reverse proxy

Organizations are sometimes required to run applications behind a reverse proxy. Reasons may include:

  • security and auditing concerns
  • virtual hosting
  • exposing applications on restricted ports
  • SSL termination

This section provides some general guidance on how to configure common reverse proxy servers to work with WebTop.

Context

By default, the WebTop URL is http://yourhost:8080/webtop. In such case, the context, which is the part of the URL just after the domain name and the port, is webtop. Basically context name follow the base .war file name. In the instance where WebTop needs to be proxied at a different base path you must change the public path by editing a settings value.

Apache httpd

If you want to serve WebTop through Apache httpd you need to satisfy these mod requirements:

Example: Reverse Proxy on Restricted Ports

Scenario: You need to expose WebTop on restricted port 80. Instead run your reverse proxy on the restricted port 80 and the application server on the default port 8080. End users will access WebTop using the virtual host URL http://www.example.com/webtop instead of http://localhost:8080/webtop. This example uses the default content path (/webtop). Ensure your external hostname (www.example.com) routes to your reverse proxy server. Keep in mind that providing services behind a non encrypted port is unsafe and discouraged, please prefer using the secure port configuration.

Apache httpd

The example assumes that Apache httpd is properly configured with the following modules: mod_proxy, mod_proxy_wstunnel, mod_rewrite, mod_headers.

<VirtualHost *:80>
  ServerName www.example.com
  ServerAdmin admin@example.com
  ErrorLog logs/www.example.com/error.log
  CustomLog logs/www.example.com/access.log common

  RequestHeader unset X-Forwarded-For

  ProxyPreserveHost On
  ProxyPass /webtop/push ws://localhost:8080/webtop/push
  ProxyPass /webtop http://localhost:8080/webtop
  ProxyPassReverse /webtop http://localhost:8080/webtop

  RewriteEngine on
  RewriteCond %{QUERY_STRING} ^((?!X-Atmosphere-Transport=websocket).)*$ [NC]
  RewriteRule ^/webtop/push(.*)$ http://localhost:8080/webtop/push$1 [P]
</VirtualHost>

Example: Reverse Proxy SSL Termination

Scenario: Your organization has standardized a reverse proxy to handle SSL certificates and termination. The reverse proxy virtual host will accept HTTPS requests on the standard port 443 and serve content from WebTop running on the default non-restricted HTTP port 8080 transparently to end users. End users will access WebTop using the virtual host URL https://www.example.com/webtop instead of http://localhost:8080/webtop. This example uses the default content path (/webtop). Ensure your external hostname (www.example.com) routes to your reverse proxy server. To test your configuration, review the steps to generate a self-signed SSL certificate for reverse proxy servers.

Apache httpd

The example assumes that Apache httpd is properly configured with the following modules: mod_proxy, mod_proxy_wstunnel, mod_rewrite, mod_headers, mod_ssl.

<VirtualHost *:443>
  ServerName www.example.com
  ServerAdmin admin@example.com
  ErrorLog logs/www.example.com/error.log
  CustomLog logs/www.example.com/access.log common

  SSLEngine on
  SSLCertificateFile "example.pem"
  SSLCertificateKeyFile "example.key"

  RequestHeader unset X-Forwarded-For

  ProxyPreserveHost On
  ProxyPass /webtop/push ws://localhost:8080/webtop/push
  ProxyPass /webtop http://localhost:8080/webtop
  ProxyPassReverse /webtop http://localhost:8080/webtop

  RewriteEngine on
  RewriteCond %{QUERY_STRING} ^((?!X-Atmosphere-Transport=websocket).)*$ [NC]
  RewriteRule ^/webtop/push(.*)$ http://localhost:8080/webtop/push$1 [P]
</VirtualHost>

Configuration

Properties

WebTop supports some configuration and debugging settings that can be enabled through Java properties to control application behaviour. Properties can be specified in two ways:

  1. Startup/System property: these properties are usually set by passing the -D flag to the Java virtual machine. This is the classic operative mode and so no other configuration is needed.
  2. WebTop property: these properties are defined in a specific property file that is loaded during startup. This allow to not fill up the Java command-line, making configuration more clear.

In order to enable this second operative mode, the startup/system property webtop.etc.dir must be specified firstly, this will instruct the application where to find customized configuration files. Then the property file will be looked-up using the following logic:

  1. Startup process tries to find a file called webtop.properties in ${PROP_ETC_DIR} directory.
  2. Then, it checks the file webtop.properties in ${PROP_ETC_DIR}/${WEBAPP_NAME} directory.

If valid files can be found in both locations, properties will be merged keeping precedence to the most specific file (the second one).

Note

${PROP_ETC_DIR} is the value of webtop.etc.dir system property and ${WEBAPP_NAME} is the web-application context-name (without any version info).

Please refer to this page to extract a list of supported properties.

Database

Database configuration relies on a specific configuration file that will be looked-up following the sequence below:

  1. Startup process tries to find a file called data-sources.xml in ${PROP_ETC_DIR}/${WEBAPP_NAME} folder.
  2. If no such file is found, it checks the file data-sources.xml in META-INF folder inside the application context. Note that this file is always available but it contains a default configuration.

Note

Where ${PROP_ETC_DIR} is the value of webtop.etc.dir system property and ${WEBAPP_NAME} is the web-application context-name (without any version info).

Warning

In order to look for external configuration files, the system property webtop.etc.dir must be specified pointing to a valid location. See above.

Logging

Warning

Starting from WebTop Core 5.7.0 is no longer necessary (and discouraged) to edit the logback.xml file in order to control log output location and type.

By default WebTop will log every message in the webapps’s standard output, the Tomcat’s catalina.out file. If you want to change this default behaviour you need to set some JVM global variables (or set them into WebTop property file discussed above):

  • webtop.log.dir
    Directory where to store log files. Defaults to /var/log/webtop.
    This is only used if the target is file.
  • webtop.log.file.basename
    The base filename of the log file (extension .log will be automatically appended). Note that appenders may append some other text to it. (eg. webtop.2019-01-01)
    Defaults to the webapp’s full context name (including context version if present).
    This is only used if the target is file.
  • webtop.log.file.policy
    The policy to apply when writing main (application) log file. Defaults to rolling.
    - simple: Writes to straight file (any rolling policy support is demanded to OS).
    - rolling: Writes to a file using a rolling appender. Currently only time-based policy is supported: 15days of max history with 150MB of total size cap.
    This is only used if the target is file.
  • webtop.log.target
    Specifies the destination used for writing main (application) log entries. Defaults to console.
    - console: Writes log entries to Tomcat’s standard output.
    - file: Writes log entries to a file.
  • webtop.log.auth.target
    Specifies the destination used for writing auth log entries. Defaults to none.
    - none: Output disabled.
    - file: Writes log entries to a file (whose name is the basename with _auth suffix appended).
    - syslog: Writes log entries to a remote syslog (see below for hostname and port defaults).
    @since: 5.10.0
  • webtop.logback.syslog.host
    Specifies the hostname of the remote syslog server used by syslog appender. Defaults to localhost.
    @since: 5.10.1
  • webtop.logback.syslog.port
    Specifies the port of the remote syslog server used by syslog appender. Defaults to 514.
    @since: 5.10.1

Due to some differences between components logging needs, the logging level cannot be set using a single variable like above. The logback.xml file is refreshed every 30s, so you can control your desired logging level by manually updating the level value in correspondence of each <logger> elements.

Installation instructions available from GitHub